In advanced integrated circuit technology, device dimensions are scaled down. Various factors degrade the performance of the integrated circuit. The electro-migration (EM) issue is impacted by the structure and dimensions of under bump metal (UBM) in the backend of line. On the other side, changing the structure and dimensions of the UBM intended to improve EM performance may cause other issue, such as bump to bride bridging. The bump fatigue performance is degraded. Therefore, a structure of an UBM and the method making the same are needed to address the above issue.